From: Lee Corbin (lcorbin@tsoft.com)
Date: Wed Feb 12 2003 - 21:00:30 MST
Some separate discussions in the thread Parallel Universes
really need breaking out. I hope everyone tries.
gts writes
> Max M wrote:
>
> > Hmm ... and nobody sees the paradox in that the infinite universes
> > would take an infinite amount of energy? The idea smack of paranormal
> > claims that cannot be tested.
In the Tegmark level one universe, there are infinitely many galaxies.
Yes, that means infinitely much energy. What is the problem?
> The proper word is "indefinite" rather than "infinite" when describing
> the number of supposed universes in the multiverse. I try to point this
> out every so often.
If the universe is ergodic (uniform matter distribution levels
higher than of 10^24 meters---100 million light years), then
there is a galaxy for each positive integer. Thus the cardinality
of the set of galaxies is aleph-zero. Of course, no particular
galaxy is at an infinite distance, just as no particular integer
is infinitely far from zero. (In level two, Tegmark discusses
universes that *are* further away than any finite quantity.
There really is no substitute for reading this most wonderful
of papers: http://it.arXiv.org/abs/astro-ph/0302131
> The quasi-religious word "infinite" always tends to enter into
> discussions of MWI, probably for the same reason that words like
> "eternity" enter into discussions of religion.
I consider both infinite and eternal (or eternity) to
have reputable referents, in either physics or religion.
Moreover, about MWI---David Deutsch says on p. 211 of
"The Fabric of Reality" that the number of universes
is a continuum, meaning that there are more than merely
countably many of them (as with the integers). The
number of universes in MWI is 2^aleph-null, at least
aleph-one.
Lee
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